a) remove tracks from the Archos; how many have been removed in the last

two weeks?
None.

b) add tracks to the Archos; how many have been added in the last two
weeks?
About 30.

c) what proportion of tracks have been on your Archos for over a month?
Almost all. I very rarely remove the tracks, as I like to take
everything I have with me when moving around. The 6 GB player contains
the whole collection, and still has around 500 MB free.